In one of wire connecting devices of a prior art, a press-insert terminal is inserted into a terminal accommodation space of a terminal holder unit. A covered electric wire is inserted into a holder-side groove and then the press-insert terminal is press inserted into the terminal accommodation space. A part of an insulating coating portion of the wire is removed when the press-insert terminal is inserted into the terminal accommodation space, so that the press-insert terminal is electrically connected to the covered electric wire.
However, in the wire connecting device of the above prior art, the covered electric wire is not stably held in the holder-side groove and not firmly maintained at its wire assembled position.